One-way glass cube



FIG. 1 is a perspective view of a one-way glass cube; the cube is hollow and the reflective surface of the one-way glass faces inwardly; and,

FIG. 2 is a sectional view of the one-way glass cube taken along line 2-2 in FIG. 1. 

The ornamental design for a one-way glass cube, as shown and described. 